报告题目：A new type of double exponential Cox model with a gamma frailty
报告人简介：周洁，副教授，就职于首都师范大学数学科学学院，主要从事生存分析、复发事件与纵向数据的研究，在JASA，Biometrics, Statistica Sinica等国内外重要统计学杂志上发表SCI论文20余篇，主持多项北京市科研项目以及3项国家自然科学基金项目。
报告摘要：Cox model is the most popular model for analyzing survival data. Gamma frailty is a commonly used method for modeling the heterogeneity of subjects. However, under the gamma frailty model, the marginal hazard would lead to effects of
covariates that eventually die out as failure time t heads to infinity. To overcome this defect of the gamma frailty model, we propose a new type of double exponential gamma frailty Cox model. For the inference on the proposed models, maximum likelihood estimation is carried out and the resulting estimators are demonstrated to be consistent and asymptotically normal. Numerical simulation studies are conducted to evaluate the finite sample behaviors of the proposed estimators. Finally, an application to a medical cost study of chronic heart failure patients from the University of Virginia Health System is provided for illustration.